Your title poses a question. Do your other children exhibit similar behaviour? If not, then you've answered the question. ODD married with ADHD can lead to serious behavioural issues. The term 'conduct disorder' is more controversial. Some don't like the term as it's a precursor and suggests eventual psychopathy. The reality is that most teens diagnosed with conduct disorder do not go on to be psychopaths and many eventually end their anti-social behaviour. Similarly, ADHD symptoms often dissipate after the teenage years and some young adults even appear to 'grow out of it'.
It's difficult to give advice on your current situation. Given a supportive environment and good therapy, many young teens will improve and can be unrecognizable by 17 or 18. However, with two other younger children at home, is there a risk to their development by keeping Brooke at home? At age 14, there's a reasonable chance that her behaviour could escalate before it subsides.
You seem like you're at wit's end. Try to remember that you are a person as well. Beyond being the parent of a seriously challenged daughter, Jade is a person who has value and is not going round fighting and stealing. You are entitled to be safe from your daughter. Give yourself permission to make rational decisions about Brooke that also take into consideration your ability to cope. Also, forgive yourself for your filthy mouth. You are human and this situation is extreme. But, in future, try to control it - before going off, give yourself time to take three very deep breaths. Hopefully, it'll give you time to get back in control and avoid more regrettable words.
One last point, if you make the decision that Brooke can't live at home, keep the communication channels open and keep trying to show your affection for her. Treat the arrangement as temporary until Brooke's no longer a threat and you both agree that it's time for her to be at home. There are many people on this forum who've had to divorce their adult children and sever communication because they've been repeatedly abused over years. However, at 14, there is still plenty of hope but only if there is someone in her life who will encourage and mentor her to make good decisions.
